Modeling of Radio-Frequency and Direct Current Glow Discharges in Argon

A hybrid modeling network, consisting of Monte Carlo, fluid and collisional-radiative models for the various plasma species (electrons, argon ions, fast argon atoms, argon atoms in various excited levels, copper atoms and ions, also in various energy levels) has been developed for glow discharges, both in the direct current (dc) and the capacitively coupled radio-frequency (rf) mode at 13.56 MHz. The typical results, like electrical characteristics, densities of the various plasma species, collisions in the plasma, cathode-sputtering and optical emission intensities, are presented and compared between the two operation modes. It is found that for the same input power and pressure, the rf-mode requires lower voltages than the dc-mode, in good correlation with experiment. The cathode-sputtering (erosion) rate and the optical emission intensities are, however, calculated to be more or less similar for both discharge modes, which is also in agreement with experiment. (author)